It has heretofore been proposed that an insulating board may be made by applying fibrous sheet to a block of foamed thermoplastic material by applying heat to the fibrous sheet and thereafter assembling the sheet to the block of resin material and continuing the application of heat with pressure for a short period of time. One of the problems with such a method is that the foam must be in a rigid form which makes the method difficult to practice in thin insulating boards since the foam material tends to be quite rigid so that when the thin material is rolled for storage, it has a configuration which makes it difficult to handle and thereby tends to crack or break as it is removed from the rolls.
Accordingly, among the objects of the invention are to provide a method for making thin insulating board and particularly to make such board from foamed thermoplastic sheet material that has been provided in a roll that is at ambient temperature.